var centerLatitude = 21.036888;
var centerLongitude = 105.83402;
var startZoom = 13;
var map;
function initialize() {
	
    var latlng = new google.maps.LatLng(centerLatitude, centerLongitude);
    var options = {
     	zoom: startZoom,
     	center: latlng,
     	mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    map = new google.maps.Map(document.getElementById("map"), options);
    return map;
}
function addMarker(Lat,Lon,img, contentString){
	var infowindow = new google.maps.InfoWindow({
    	content: contentString
	});
	var marker = new google.maps.Marker({
		position: new google.maps.LatLng(Lat, Lon),
		map: map,
		icon: img
	});
	google.maps.event.addListener(marker, 'click', function() {
  		infowindow.open(map,marker);});
}
//window.onload = initialize;